BTW, I *think* the schematic for the ATX-80 is wrong; it shows the oscillator as a NAND gate; the CD4001 is a NOR gate. It messed me up when I first started to check it out since I figured it would just start oscillating because the input is tied high. Needless to say, it didn't :)! The schematics by Rik are at http://www.qsl.net/on7yd/atx80.htm.